<!DOCTYPE html>
<html>
<head>
  <meta charset="UTF-8">
  <title>Document</title>
  <script src="vue.js"></script>
</head>
<body>
  <div id="app">
    <input type="text" v-focus="false">
  </div>
  <script>
    Vue.directive('focus', {
      inserted (el, binding) {
        if (binding.value) {
          el.focus()
        }
      }
    })
    var vm = new Vue({ el: '#app' })
 </script>
</body>
</html>